Trimming mechanism for sewing machines



@m'ie W35 J. M. WASHBURN 2,017,382

TRIMMING MECHANISM FOR SEWING MACHINES Filed Jn. 24, 1935 lumen/601': YJohn/M W lvburn Ms Attarneys Patented Oct. 15, 1935 UNITED STATES PATENTOFFICE TRIMDIING MECHANISM FOR SEWING MACHINES Application January 24,1935, Serial No. 3,317

5 Claims.

This invention relates to trimming mechanism for sewing machines and isespecially directed to improvement of means for supporting andpermitting adjustment of a movable cutter in trio. ming mechanism of thetype employed in the well known Merrow overseaming machines asillustrated and described in United States Patent No. 733,760, grantedto William H. Stedman, July 14th, 1903, also in United States Patent No.1,207,063, granted to Joseph M. Merrow, December 5th, 1916.

Primarily the object of the invention is the provision in trimmingmechanism of parts which are of minimum weight consistent with requiredstrength, combined in an efficient arrangement including a cuttersupporting carriage, means for adjustably securing the carriage to acarrier, and a clamp for securing a cutter blade to the carriage.

In the accompanying drawing,

Figure 1 is a side view of a cutter carrier and associated partsembodying my invention.

Figure 2 is a front view of the parts shown in Fig. 1.

Figure 3 is a sectional view on line 3--3 of Fig. 2.

Figure 4 is a sectional view on line 4-4 of Fig. 1.

Figures 5 and 6 are detail views of a cutter carriage.

Figures 7 and 8 are detail views of a cutter carriage clamping nut.

Figures 9 and 10 are detail views of a cutter clamping element.

It will be noted that Figs. 3 to 10 inclusive are drawn to an enlargedscale.

Referring to the drawing, a cutter carrier such as employed in a Merrowoverseaming machine is designated by I. It is supported for oscillatorymovement on a rock shaft 2 and is actuated by an eccentric 3 driven byshaft 4. The eccentric is fitted with a block 5 which is engaged by theyoke portion 6 of the cutter carrier, the latter having at its free enda laterally extended arm I which is channeled throughout its length withan undercut groove 8. Converging toward its outer end, arm 1 is taperedon its rear side 9 to reduce bulk where it is not required for strength.For the same reason the edges of the arm are beveled as at l and H.Also, as at l2, l3 and M, the cutter carrier is recessed to reduce itsweight without materially affecting its strength. The groove 8 forms inarm I a guideway in which the cutter carriage l may be adjustablysecured. Carriage I5 is formed of a substantially flat plate having atongue l5 and recess I! on its rear side and a diagonally extendingchannel l8 on its front side. Means serving to adjustably securecarriage l5 to the cutter carrier arm I and to adjustably secure cutterblade IS in the diagonal a channel l8, include a nut 20 and clampingelement 2|. Tongue l6 of the cutter carriage and nut 20 are each formedto engage the undercut groove 8 in arm I, and the nut is provided with ahead 22 to engage recess I! in the cutter carriage i5. The clamp 21,formed to straddle the cutter blade 19, is of substantially U-shapehaving legs 23 and 24 adapted respectively to engage the surface of thecutter carriage and that flange 25 of the cutter blade which is formedto fit channel I8 in the carriage. A screw 26 is employed to impartthrust to clamp 2! to hold the cutter blade to the carriage and also toimpart thrust to nutto hold the carriage I 5 to the carrier arm 1, therespective pressures involved being opposed to 20 each other. Thethreaded end of screw 26 engages a tapped hole 21 in nut 20 and the headof the screw engages the clamp at its intermediate section which isrecessed at 28 to receive the body of the screw. A second tapped hole 29is provided in nut 20 to engage screw 30 which serves to clamp thecarriage l5 upon its supporting arm and thus to maintain its positionthereon while screw 26 is loosened to permit adjustment of the cutterblade. The carriage I5 is 30 provided with holes 3| and 32 to receivethe respective screws 26 and 30. Extended from the clamp 2| is aperforated wing 33 which serves for convenience in handling and forpassage of a thread.

Having thus described my invention, what I claim is,

1. A trimming mechanism for sewing machines including in combination, anoscillatory carrier having an arm extending transversely to its plane ofmovement and provided with a groove, a cutter holder and a nut, eachhaving a tongue to match the groove in the arm of the carrier andslidable therein, and a screw extending through the holder to engage thenut whereby tightening of the screw will clamp the holder to the arm.

2. A trimming mechanism for sewing machines including in combination, anoscillatory carrier having an arm extending transversely to its plane ormovement and provided with a groove, a cutter holder and a nut, eachhaving a tongue to match the groove in the arm of the carrier andslidable therein, and a screw extending through the holder to engage thenut, the latter having a head to engage a recess in the holder.

having a tongue on one side to match the groove in the arm of thecarrier and a recess adjacent one end of the tongue, a nut also having atongue to match the groove in the carrier and a head to match the recessin the holder, both the holder and the nut being slidably engageablewith the carrier, and a screw extending through the holder to engage thenut.

4. A trimming mechanism for sewing machines including in combination, anoscillatory carrier having an arm extending transversely to its plane ofmovement and provided with an undercut groove, a cutter blade, a holderfor the cutter blade comprising a substantially flat plate having on oneside a tongue to match the groove in the arm of the carrier and a recessadjacent one end of the tongue and on the other side a channel toreceive the cutter blade, a nut having a tongue to match the groove inthe carrier and a head to match the recess in the holder, a clamp ofwhich respective portions engage the cutter holder and the cutter blade,and a screw engaging the clamp on one side of the holder and the nut onthe other whereby the cutter blade may be clamped to the holder and theholder clamped to the carrier.

- 5. A trimming mechanism for sewing machines including in combination,an oscillatory carrier having an arm extending transversely to its planeof movement and provided with an undercut groove, a cutter blade, aholder for the cutter blade comprising a substantially flat plate havingon one side a tongue to match the groove in the arm of the carrier andon the other side a channel to receive the cutter blade, a nut engagedwith the groove of the carrier and slidable therein with the tongue onthe holder, a clamp of which respective portions engage the cutterholder and the cutter blade, a screw engaging the clamp and the nut anda screw engaging the holder and the nut.

JOHN M. WASHBURN.

